a. Field of the Invention
This invention relates to prostanoic acid derivatives capable of inhibiting the actions of prostaglandins, to processes for preparing these derivatives and to methods for using said derivatives.
B. Prior Art
The number of substances which inhibit prostaglandin actions is relatively small. See, for example, the review by J. H. Sanner, Arch. Intern. Med., 133, 133 (1974). Chemically the most interesting of the substances fall into three catagories: dibenzoxazepines, phosphorylated polymers of phloretin and 7-oxaprostaglandin analogs. Apparently, only one report has appeared describing prostaglandin inhibiting properties for compounds having the total carbon skeleton of a prostanoic acid. In this instance, the antiprostaglandin effect was a desensitization of rat uterus and gerbil colon tissue to prostaglandin E.sub.2 by the prostaglandin analogs 11,15-epi-prostaglandin E.sub.2 and ent-11,15-epi-prostaglandin E.sub.2, E. J. Corey, et al., J. Org. Chem., 37, 3043 (1972); on the other hand, these prostaglandin analogs produced a prostaglandin-like effect on the tissues indicating mixed agonist and antagonist properties for the analogs.
In accordance with the present invention a series of compounds having the prostanoic acid carbon skeleton are disclosed; the compounds inhibit the actions of prostaglandins in the manner of a specific prostaglandin antagonist in that they do not exhibit appreciable agonist properties.
One of the compounds contained herein, i.e. 2-(3-hydroxy-loctynyl)-5-oxocyclopentaneheptanoic acid, and its lower alkyl esters (formula l in which A is --C.tbd.C--CHOH-- and R.sup.1 is hydrogen or lower alkyl) have been disclosed before, see West German Offenlegungsschrift 2,318,595, published 1973; however, the activities reported therein for these compounds were prostaglandin-like in nature.